| Abstract |
Magnetic Resonance Imaging (MRI) is a non-destructive and element-specific technique to probe complex systems in a spatially-resolved manner. The GEM facility at ETH Zurich will implement both high- and low-field MRI technology for reactive transport analyses of geothermal fluids in 3D-printed porous and fractured media. The primary instrument uses a 5.6 T magnet, with a field-of-view over a 20 cm diameter sphere. Further, a custom low-field 36 mT MRI device will be implemented as a portable and cost-effective modality, while also probing unpaired-electron centers. The latter can also leverage dynamic nuclear polarization (DNP) to enhance low-field ¹H and ¹³C signals by factors of 660 and 2600 in their theoretical limit, respectively, offering concomitant experimental time savings of five and six orders of magnitude. Both devices offer multinuclear capabilities, including the detection of ¹H, ⁷Li, ¹³C, ¹⁹F, ²³Na, ²⁹Si, ³¹P, ¹²⁹Xe, etc., which is critical for analyzing multicomponent geofluids (e.g., H₂O, brine, H₂, CH₄, etc.). Unique additive manufacturing is used to 3D print polymers and ceramics that represent scaled-down geological reservoirs. These 3D-printed reservoirs can be studied in the MRI scanners and subjected to the same conditions as found in the Earth’s crust (i.e., >100 °C and >100 bar) for in-situ analyses of 3D velocity, pressure, and temperature fields. In this presentation, we will show preliminary results of velocity field and temperature data acquired for 3D-printed geological reservoirs on 3 T commercial hospital MRI scanners. Preliminary results from the development of a unique 36 mT MRI device will also be presented. |